Rear main seal replacement

While replacing the clutch and transmission, my friend Mike suggested we replace the rear main seal while we were at it. The rear main seal could well have been a breed of dog as far as I was concerned but I was very glad we ordered the replacement seal. One the transmission has been removed, the flywheel is exposed.

To access the rear main seal, remove the 6 17mm bolts holding the flywheel on and remove the flywheel. The rear main seal is the large seal (similar diameter to a CD) behind the transmission. With the pilot bearing (small bearing in the middle it seals the rotating crankshaft and engine internals from the outside world.

Being a Lotus I should have expected it but, it was filthy (dirt and oil) and was clearly leaking. So far on my Esprit I've had leaks at the front hub, rear main seal and still have the cam tower's to do (nothing major, but enough to cause a detailing nightmare). I guess it's like painting the Golden Gate bridge, by the time I've finished with that one, it'll be time to start over.

To replace the seal you must remove the seal cover which is held on by 7 allen bolts.

Please ensure that the engine oil has been drained, otherwise it'll get very messy indeed.

The rear main seal comes out with the cover. Clean the area, and the seal cover. Apply gasket sealer to the seal cover and replace and secure with the 7 bolts using threadlocker.

Remove the pilot bearing and press in (or tap with a hammer) the new pilot bearing.

Now using the special rear main seal tool from Lotus insert the seal. The new seal slides over the outside of the special tool which is aligned with the pilot bearing and is pressed in. It was awkward enough to get the seal to fit into the cover with the special tool, so I imagine it would be next to impossible to do with the tool, without damaging the seal.